The head of a golf club has a hosel portion to which one end of a shaft is secured. A grip for a player to grip is secured on the other end of the shaft and the hosel portion is formed to protrude upwards from the head. Consequently, the weight of the hosel portion causes the head to have a center of gravity of a high position. Making the center of gravity of the head lower, it becomes easier to hit a ball highly upwards as well as hit the ball at the position of center of gravity. Therefore, carried distance of a ball becomes long, which is advantageous especially for a golfer having a low head speed in club swing.
Various heads are proposed in which hosel portions are made to have a reduced weight in order to make heads have a low center of gravity. The heads disclosed in Japanese Patent Publication No. H09-108388, A1 (Patent Document 1) and Japanese Patent Publication No. H09-117536, A1 (Patent Document 2) is such that their hosel portions are formed of a material with a specific gravity less than that of the head. However, because the hosel portion and the head are formed of different materials in either of Patent Document 1 or Patent Document 2, they have such disadvantages that expense for producing the golf clubs increases, there is a fear of the hosel portion getting out of the head or it is difficult to connect the hosel portion with the head in a highly precise manner.
The head disclosed in Japanese Patent Publication No. 2005-52401, A1 (Patent Document 3) is composed without a hosel portion so that a hole having a form other than circular shape is formed in the head, a socket of a light weight material is fixed to the hole and the shaft is fixed to the socket. However, because the head of Patent Document 3 necessitates a socket of a member other than the head, it has such disadvantages that expense for producing the golf club increases and it is difficult to fix the socket to the hole of the head in a highly precise manner. Moreover, without a hosel portion, strange fearing occurs in time of addressing, thus making addressing less easy.